Fuel sender

Blacktooth

New Member
Joined
Sep 26, 2020
Messages
2
Just over 10k miles on my 2018 Super T and the fuel gauge stays on full for about 90 miles then starts tracking fuel remaining accurately.
WTF
 

Sierra1

Well-Known Member
Joined
Nov 7, 2016
Messages
14,812
Location
Joshua TX
My first block goes away at about 70 miles. I really like my throttle :rolleyes:.
 
Last edited:

Cycledude

Well-Known Member
Joined
Jan 29, 2016
Messages
3,997
Location
Rib lake wi
My fuel gauge seems reasonably accurate, I usually reset the trip meter when refueling that way it’s pretty easy to determine how accurate the fuel gauge actually is.
 

Alexander

Active Member
Joined
Mar 8, 2020
Messages
83
Location
Kansas City
This is typically caused by the shape of the tank, and the location of the float arm on the fuel pump assembly.

When the tank is full, the float arm stays maxed out at the topmost position (because the float is submerged in fuel) until you've burned enough fuel for the float arm to start dropping. Aaaand the fuel gauge won't start dropping until the fuel level is below the maximum float arm angle.

To those who don't know, the float arm is attached to a rheostat (variable resistor, a three-wire device -- power, ground, and signal) which alters electrical current based on the fuel level inside the tank. As the fuel level drops, the float arm drops, which causes a measurable voltage drop across the rheostat -- and that's what's driving the fuel level gauge.

It's horrible on cars with V-shaped fuel tanks. They report "full" forever because there's a lot of fuel volume at the top of the tank, but over time, the fuel level accelerates toward empty because the volume of the tank narrows toward the bottom. So you drive 20 miles and suddenly lose a quarter-tank of fuel on the gauge. Difficult to explain, but hopefully that makes sense.

My first bike didn't even have a fuel level gauge, so I'm thrilled with even somewhat inaccurate ones.
 

josephgleyzer

New Member
Joined
Sep 13, 2020
Messages
8
Location
Israel
I did a very stupid thing and a plastic tube felt in to the fuel tank. So I made a video on how to disassemble the fuel pump.
(Video is in hebrew, but there are english subtitles).
Might be useful:
 
Top